Just before Christmas, California Gov. Jerry Brown (D) announced that he would pardon the sentences of 91 people in the state who had served time and had been rehabilitated — part of what has become an annual Christmas Eve tradition for the governor.

Many were surprised to hear that Robert Downey Jr. was among the 91 people pardoned; the "Iron Man" actor served time in prison on a drugs and weapons conviction in the late 1990s. The actor "earned a full and unconditional pardon" because he "has lived an honest and upright life, exhibited good moral character, and conducted himself as a law-abiding citizen," the pardon read. The pardon doesn't mean a clean record, but allows the actor to serve on juries, for example.

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Most of the sentences pardoned by Gov. Brown were non-violent drug offenses, crimes which have only recently come under scrutiny for the severity of sentences they incurred. Along with Gov. Brown's Christmas Eve tradition, other high-profile pardons and sentence commutations have been bubbling up in the news recently — though few have been elevated to such celebrity status. Earlier in December, President Barack Obama commuted the sentences of 95 people, and pardoned two others' sentences, most of which were drug-related.

There's a slight difference between commutations and pardons: the former is more or less a literal get out of jail card; the latter can be that, and also the restoration of civil rights like the right to vote and serving on a jury. Neither necessarily wipes a person's record clean, but both are a major step in righting some of the wrongs inflicted by harsh drug laws and the punitive vacuum that is mass incarceration — especially when it comes to non-violent drug offenses.

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Recent years have seen the beginnings of a historic shift away from the zero-tolerance drug enforcement policies and perfunctory sentencing of recent decades in criminal justice. But some say that powerful figures like the president could go further. As the New Yorker's Jeffrey Toobin wrote recently:

"Obama could make the case for pardons or commutations on an individual-by-individual basis, or he could establish a broader rule — that, say, every nonviolent drug offender with just a single conviction, or possession of a certain quantity of drugs, would be eligible."

If anything, pardons and commutations by elected officials draw attention to just how many of the nation's incarcerated are perhaps eligible or deserving of consideration. Just under half of federal inmates are serving time for drug offenses, with about 16 percent of the more than 1.3 million inmates in state prisons listing drug offenses as their most serious crime. Certainly not all of those inmates' sentences are steadfast.

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Other indications show that while prisons still swell with inmates who could be eligible to have their crimes revisited, the sentiment is at least on the mind of incarceration officials. In October, the Justice Department announced it would begin releasing about 6,000 federal inmates largely locked up for drug offenses with too-harsh punishments. The U.S. Sentencing Commission, which sets sentencing guidelines for federal crimes, said that a change in drug offense sentencing could ultimately lead to tens of thousands of subsequent early releases.